Manage multiple form (validation) in stepper flutter
Use a list GlobalKey to keep each form's key and in Continue call formKeys[currStep].currentState.validate()
formKeys is global variable, In your case for separate form file you can use global library to access it Global Variables in Dart
For demo, each from only have one field
code snippet
List<GlobalKey<FormState>> formKeys = [GlobalKey<FormState>(), GlobalKey<FormState>(), GlobalKey<FormState>(), GlobalKey<FormState>()];
...
onStepContinue: () {
setState(() {
if(formKeys[currStep].currentState.validate()) {
if (currStep < steps.length - 1) {
currStep = currStep + 1;
} else {
currStep = 0;
}
}
full code
import 'package:flutter/material.dart';
//import 'package:validate/validate.dart'; //for validation
void main() {
runApp( MyApp());
}
List<GlobalKey<FormState>> formKeys = [GlobalKey<FormState>(), GlobalKey<FormState>(), GlobalKey<FormState>(), GlobalKey<FormState>()];
class MyApp extends StatefulWidget {
@override
State<StatefulWidget> createState() {
return MyAppScreenMode();
}
}
class MyData {
String name = '';
String phone = '';
String email = '';
String age = '';
}
class MyAppScreenMode extends State<MyApp> {
@override
Widget build(BuildContext context) {
return MaterialApp(
theme: ThemeData(
primarySwatch: Colors.lightGreen,
),
home: Scaffold(
appBar: AppBar(
title: Text('Steppers'),
),
body: StepperBody(),
));
}
}
class StepperBody extends StatefulWidget {
@override
_StepperBodyState createState() => _StepperBodyState();
}
class _StepperBodyState extends State<StepperBody> {
int currStep = 0;
static var _focusNode = FocusNode();
GlobalKey<FormState> _formKey = GlobalKey<FormState>();
static MyData data = MyData();
@override
void initState() {
super.initState();
_focusNode.addListener(() {
setState(() {});
print('Has focus: $_focusNode.hasFocus');
});
}
@override
void dispose() {
_focusNode.dispose();
super.dispose();
}
List<Step> steps = [
Step(
title: const Text('Name'),
//subtitle: const Text('Enter your name'),
isActive: true,
//state: StepState.error,
state: StepState.indexed,
content: Form(
key: formKeys[0],
child: Column(
children: <Widget>[
TextFormField(
focusNode: _focusNode,
keyboardType: TextInputType.text,
autocorrect: false,
onSaved: (String value) {
data.name = value;
},
maxLines: 1,
//initialValue: 'Aseem Wangoo',
validator: (value) {
if (value.isEmpty || value.length < 1) {
return 'Please enter name';
}
},
decoration: InputDecoration(
labelText: 'Enter your name',
hintText: 'Enter a name',
//filled: true,
icon: const Icon(Icons.person),
labelStyle:
TextStyle(decorationStyle: TextDecorationStyle.solid)),
),
],
),
)),
Step(
title: const Text('Phone'),
//subtitle: const Text('Subtitle'),
isActive: true,
//state: StepState.editing,
state: StepState.indexed,
content: Form(
key: formKeys[1],
child: Column(
children: <Widget>[
TextFormField(
keyboardType: TextInputType.phone,
autocorrect: false,
validator: (value) {
if (value.isEmpty || value.length < 10) {
return 'Please enter valid number';
}
},
onSaved: (String value) {
data.phone = value;
},
maxLines: 1,
decoration: InputDecoration(
labelText: 'Enter your number',
hintText: 'Enter a number',
icon: const Icon(Icons.phone),
labelStyle:
TextStyle(decorationStyle: TextDecorationStyle.solid)),
),
],
),
)),
Step(
title: const Text('Email'),
// subtitle: const Text('Subtitle'),
isActive: true,
state: StepState.indexed,
// state: StepState.disabled,
content: Form(
key: formKeys[2],
child: Column(
children: <Widget>[
TextFormField(
keyboardType: TextInputType.emailAddress,
autocorrect: false,
validator: (value) {
if (value.isEmpty || !value.contains('@')) {
return 'Please enter valid email';
}
},
onSaved: (String value) {
data.email = value;
},
maxLines: 1,
decoration: InputDecoration(
labelText: 'Enter your email',
hintText: 'Enter a email address',
icon: const Icon(Icons.email),
labelStyle:
TextStyle(decorationStyle: TextDecorationStyle.solid)),
),
],
),
)),
Step(
title: const Text('Age'),
// subtitle: const Text('Subtitle'),
isActive: true,
state: StepState.indexed,
content: Form(
key: formKeys[3],
child: Column(
children: <Widget>[
TextFormField(
keyboardType: TextInputType.number,
autocorrect: false,
validator: (value) {
if (value.isEmpty || value.length > 2) {
return 'Please enter valid age';
}
},
maxLines: 1,
onSaved: (String value) {
data.age = value;
},
decoration: InputDecoration(
labelText: 'Enter your age',
hintText: 'Enter age',
icon: const Icon(Icons.explicit),
labelStyle:
TextStyle(decorationStyle: TextDecorationStyle.solid)),
),
],
),
)),
// Step(
// title: const Text('Fifth Step'),
// subtitle: const Text('Subtitle'),
// isActive: true,
// state: StepState.complete,
// content: const Text('Enjoy Step Fifth'))
];
@override
Widget build(BuildContext context) {
void showSnackBarMessage(String message,
[MaterialColor color = Colors.red]) {
Scaffold
.of(context)
.showSnackBar( SnackBar(content: Text(message)));
}
void _submitDetails() {
final FormState formState = _formKey.currentState;
if (!formState.validate()) {
showSnackBarMessage('Please enter correct data');
} else {
formState.save();
print("Name: ${data.name}");
print("Phone: ${data.phone}");
print("Email: ${data.email}");
print("Age: ${data.age}");
showDialog(
context: context,
child: AlertDialog(
title: Text("Details"),
//content: Text("Hello World"),
content: SingleChildScrollView(
child: ListBody(
children: <Widget>[
Text("Name : " + data.name),
Text("Phone : " + data.phone),
Text("Email : " + data.email),
Text("Age : " + data.age),
],
),
),
actions: <Widget>[
FlatButton(
child: Text('OK'),
onPressed: () {
Navigator.of(context).pop();
},
),
],
));
}
}
return Container(
child: Form(
key: _formKey,
child: ListView(children: <Widget>[
Stepper(
steps: steps,
type: StepperType.vertical,
currentStep: this.currStep,
onStepContinue: () {
setState(() {
if(formKeys[currStep].currentState.validate()) {
if (currStep < steps.length - 1) {
currStep = currStep + 1;
} else {
currStep = 0;
}
}
// else {
// Scaffold
// .of(context)
// .showSnackBar( SnackBar(content: Text('$currStep')));
// if (currStep == 1) {
// print('First Step');
// print('object' + FocusScope.of(context).toStringDeep());
// }
// }
});
},
onStepCancel: () {
setState(() {
if (currStep > 0) {
currStep = currStep - 1;
} else {
currStep = 0;
}
});
},
onStepTapped: (step) {
setState(() {
currStep = step;
});
},
),
RaisedButton(
child: Text(
'Save details',
style: TextStyle(color: Colors.white),
),
onPressed: _submitDetails,
color: Colors.blue,
),
]),
));
}
}
working demo
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Jerry Palmiotto
Updated on June 04, 2022Comments
-
Jerry Palmiotto almost 2 years
I have multiple form in each step of a Stepper, Form are in external file because in my App each Step can contain a different Form. I want that when user click on "Continue" the form will be validated and in an error situation the user will be warned. I tried to use Inherited Widget but it gives me a "null on getter". The code below: Screen that contain Steps
import 'package:flutter/material.dart'; import 'package:pberrycoffeemaker/widgets/function_appbar.dart'; import 'package:pberrycoffeemaker/widgets/inputs_0.dart'; import 'package:pberrycoffeemaker/widgets/stepper_banner.dart'; class FunctionScreen extends StatelessWidget { @override Widget build(BuildContext context) { int indexStep = 0; double bottomHeight = (MediaQuery.of(context).size.height * 40) / 100; double cardHeight = (MediaQuery.of(context).size.height * 60) / 100; double cardWidth = (MediaQuery.of(context).size.width * 85) / 100; FirstTypeInput firstTypeOfInput = FirstTypeInput(); GlobalKey<FormState> key = new GlobalKey<FormState>(); return Scaffold( body: Stack( children: <Widget>[ AppbarBack( height: bottomHeight, ), Align( alignment: Alignment(0.0, .65), child: ClipRRect( borderRadius: BorderRadius.all(Radius.circular(15.0)), child: Container( child: StepperBanner( firstTypeInputKey: key, test: 18, firstTypeInputField: {}, child: Stepper( currentStep: indexStep, onStepContinue: (){ print(StepperBanner.of(context).test); //StepperBanner.of(context).firstTypeInputKey.currentState.validate(); }, //type: StepperType.horizontal, steps: <Step>[ Step( content: firstTypeOfInput, title: Text("Theorical"), ), Step( content: //Second Step Content, title: Text("Practical")), ], ), ), decoration: BoxDecoration(color: Colors.white, boxShadow: [ BoxShadow( color: Colors.black, blurRadius: 10.0, offset: Offset(0.0, 0.75)) ]), width: cardWidth, height: cardHeight, ), ), ), ], ), ); } }
Form contained in first Step
import 'package:flutter/cupertino.dart'; import 'package:flutter/material.dart'; import 'package:flutter/services.dart'; import 'package:pberrycoffeemaker/functions/coffeeCalculation.dart'; import 'package:pberrycoffeemaker/widgets/stepper_banner.dart'; // ignore: must_be_immutable class FirstTypeInput extends StatefulWidget { final Map<String, double> submittedField = { "tds": 0.0, "ext": 0.0, "dw": 0.0, "af": 0.0, "co2": 0.0, "co2p": 0.0, "ih": 0.0, "ihp": 0.0, "wtemp": 0.0, "twh": 0.0, "alk": 0.0 }; @override State<StatefulWidget> createState() { return _FirstTypeInput(); } } class _FirstTypeInput extends State<FirstTypeInput> { Map<String, FocusNode> _focusNodes; GlobalKey<FormState> formKey; @override void initState() { super.initState(); _focusNodes = { "ext": new FocusNode(), "dw": new FocusNode(), "af": new FocusNode(), "co2": new FocusNode(), "co2P": new FocusNode(), "ih": new FocusNode(), "ihP": new FocusNode(), "wt": new FocusNode(), "twh": new FocusNode(), "alk": new FocusNode() }; } String percentageValidator(String value){ if (double.parse(value) < 0 || double.parse(value) > 100){ return "Insert value between 0 - 100"; } return null; } @override Widget build(BuildContext context) { return Form( key: StepperBanner.of(context).firstTypeInputKey, //key: widget.formKey, child: Column( children: <Widget>[ // * TDS TextFormField( //validator: percentageValidator, onFieldSubmitted: (value) { FocusScope.of(context).requestFocus(_focusNodes["ext"]); }, decoration: InputDecoration( labelText: "TDS%", hintText: "Insert TDS%", suffix: Text("%")), ), // * EXT TextFormField( onFieldSubmitted: (value) { FocusScope.of(context).requestFocus(_focusNodes["dw"]); }, focusNode: _focusNodes["ext"], decoration: InputDecoration( labelText: "EXT%", hintText: "Insert EXT%", suffix: Text("%")), ), // * Drink Weight TextFormField( onFieldSubmitted: (value) { FocusScope.of(context).requestFocus(_focusNodes["af"]); }, focusNode: _focusNodes["dw"], decoration: InputDecoration( labelText: "Drink Weight", hintText: "Insert drink weight", suffix: Text("g")), ), // * Absorption Factor TextFormField( onFieldSubmitted: (value) { FocusScope.of(context).requestFocus(_focusNodes["co2"]); }, focusNode: _focusNodes["af"], decoration: InputDecoration( labelText: "Absorption Factor", hintText: "Insert absorptio factor", suffix: Text("g")), ), // * CO2 TextFormField( onFieldSubmitted: (value) { FocusScope.of(context).requestFocus(_focusNodes["co2P"]); }, focusNode: _focusNodes["co2"], decoration: InputDecoration( labelText: "CO2", hintText: "Insert CO2", suffix: Text("g")), ), // * CO2 Precision TextFormField( onFieldSubmitted: (value) { FocusScope.of(context).requestFocus(_focusNodes["ih"]); }, focusNode: _focusNodes["co2P"], decoration: InputDecoration( labelText: "CO2 Precision", hintText: "Insert CO2 Precision", suffix: Text("%")), ), // * Internal Humidity TextFormField( onFieldSubmitted: (value) { FocusScope.of(context).requestFocus(_focusNodes["ihP"]); }, focusNode: _focusNodes["ih"], decoration: InputDecoration( labelText: "Internal Humidity", hintText: "Insert internal humidity", suffix: Text("%")), ), // * Internal Humidity Precision TextFormField( onFieldSubmitted: (value) { FocusScope.of(context).requestFocus(_focusNodes["wt"]); }, focusNode: _focusNodes["ihP"], decoration: InputDecoration( labelText: "Internal Humidity Precision", hintText: "Insert internal humidity precision", suffix: Text("%")), ), // * Water Temperature TextFormField( onFieldSubmitted: (value) { FocusScope.of(context).requestFocus(_focusNodes["twh"]); }, focusNode: _focusNodes["wt"], decoration: InputDecoration( labelText: "Water Temperature", hintText: "Insert water temperature", //TODO da decidere se settare nelle impostazioni l'unità di misura oppure mettere un dropdown sotto suffix: Text("C°|F°|K°")), ), // * Total Water Hardness TextFormField( onFieldSubmitted: (value) { FocusScope.of(context).requestFocus(_focusNodes["alk"]); }, focusNode: _focusNodes["twh"], decoration: InputDecoration( labelText: "Total Water Hardness", hintText: "Insert total water hardness", //TODO da decidere se settare nelle impostazioni l'unità di misura oppure mettere un dropdown sotto suffix: Text("PPM°|F°|D°")), ), // * Alkalinity TextFormField( focusNode: _focusNodes["alk"], decoration: InputDecoration( labelText: "Alkalinity", hintText: "Insert alkalinity", //TODO da decidere se settare nelle impostazioni l'unità di misura oppure mettere un dropdown sotto suffix: Text("PPM°|F°|D°")), ), ], ), ); } }
Inherited Class, StepperBanner:
import 'package:flutter/material.dart'; class StepperBanner extends InheritedWidget { final Map<String, double> firstTypeInputField; final GlobalKey<FormState> firstTypeInputKey; final int test; StepperBanner({Widget child, this.firstTypeInputField,this.test, this.firstTypeInputKey}) : super(child: child); @override bool updateShouldNotify(InheritedWidget oldWidget) => true; static StepperBanner of(BuildContext context) => context.inheritFromWidgetOfExactType(StepperBanner); }
Should I manage validation with Inherited Class or there are some other metods?
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StefanSpeterDev about 4 yearsHey thank you for sharing it works great and it's easy to modify up to what we need, I've searched for hours before finding on your answer!
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Dani almost 3 yearsthat's fine for when we want to validate step by step but what about if we need to validate the whole thing?
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rosh-dev851 over 2 yearsthis.formKeys.every((element) => element.currentState!.validate());